Rudy Giuliani, a 2008 GOP White House front-runner, is moving to sell the Wall Street wing of his multi-pronged business – the strongest sign yet that he’s making a serious play for the presidency, The Post has learned.

Officials at Giuliani Partners have been meeting quietly with several firms about buying the firm’s stake in Giuliani Capital Advisors, an investment banking company, sources familiar with the discussions said.

The Chicago-based investment firm is the largest arm of the former mayor’s self-named business, and may be the biggest cash cow of Giuliani’s four-unit business.

But they “get involved in . . . issues which could be politically sensitive,” said one source familiar with the discussions.

The exact price wasn’t clear, but the multimillion-dollar sale would have to be approved by the Securities and Exchange Commission.

Giuliani snatched up the firm from Ernst & Young for a reported $9.8 million just over two years ago.

Officials at Giuliani Partners, which has the controlling equity stake in the Chicago-based GCA, declined comment.

The move comes at a time when Giuliani is ratcheting up his national effort, filling holes in his campaign operation as he’s faced questions about whether he’ll commit to a run.

It also comes as his businesses are getting vetted and questions have been raised about potential conflict-of-interest issues.

The Post first reported earlier this month that Giuliani was weighing changes to his empire as he ramps up for a White House campaign.

Giuliani is still active in his other three ventures – the consulting firm, Giuliani Partners, Giuliani Safety and Security, and his law firm, Bracewell and Giuliani – and it’s unclear whether he’ll move.

GCA is the business unit that Giuliani has spent the least amount of time involved with – but it’s fraught with political headaches.

GP is privately owned, but GCA files reports with the SEC. GCA specializes in bankruptcies, and mergers and acquisitions.

Its clients have included Delta Airlines and Aloha Airlines, along with others that put GCA smack in the middle of pension issues and union fights.

The firm has upwards of 80 staffers, the largest number of employees at a Giuliani business unit.

It had a lower revenue take in 2005 than it had in previous years, before Giuliani bought it, but GCA officials have said the slowdown started before the ex-mayor took it over.

Meanwhile, Giuliani yesterday added former Bush-Cheney campaign adviser Brent Seaborn to his staff. Seaborn was involved with so-called “micro-targeting,” which helped boost GOP votes for Bush in his 2004 campaign.

He also hired Patrick Ruffini, President Bush’s Webmaster, to help with his Internet strategy.

Giuliani and Sen. John McCain are currently the two leading Republican candidates for the White House, according to recent polls.

Giuliani led the Arizona senator 32-26 in a CNN poll taken last week.

The next closest GOP candidate was former House Speaker Newt Gingrich, who indicated in an interview with Fox News Channel on Sunday that he would run only as a “last resort.”